What are some suggestions to clean all the pebbles and rubber out of a radiator? I have used compressed air and the water hose which helped but there is still an awful lot left. Will the air conditioning coil cleaners work on the rubber? Should I powerwash it at a car wash? I would think that would be too powerfull and would damage all the fins. I see a radiator comb in the Jeg's catalog. Or do I just have to use toothpicks or a pick to take forever to clean everything out and straighten any bent fins?